ResultSet基本使用和ResultSet遍历结果集

ResultSet：结果集对象，封装查询结果
next():游标向下移动一行
getXxx(参数):获取数据
Xxx:代表数据类型 如：int getInt（），String getString（）
参数：
int：代表列的编号，从1开始 如getString(1)
String：代表列名称 如 getDouble("balance");

package cn.lhy.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class JdbcDemo04 {
    public static void main(String[] args) throws Exception {
        Class.forName("com.mysql.cj.jdbc.Driver");
        Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/root", "root", "root");

        String sql = "select * from account";
        Statement sttm = conn.createStatement();

        ResultSet resultSet = sttm.executeQuery(sql);
        resultSet.next();
        String string = resultSet.getString("name");
        System.out.println(string);


        conn.close();
        sttm.close();

    }
}

package cn.lhy.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class JdbcDemo04 {
    public static void main(String[] args) throws Exception {
        Class.forName("com.mysql.cj.jdbc.Driver");
        Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/root", "root", "root");

        String sql = "select * from account";
        Statement sttm = conn.createStatement();

        ResultSet resultSet = sttm.executeQuery(sql);

        while(resultSet.next()){
            int anInt = resultSet.getInt(1);
            String name = resultSet.getString("name");
            double aDouble = resultSet.getDouble(3);
            System.out.println(anInt+"====="+name+"====="+aDouble);
        }


        conn.close();
        sttm.close();

    }
}